Pharmaceutical preparations, food supplements or other substances are often administered in what are called two-piece capsules, which are intended to be swallowed by the user. Two-piece capsules are composed of a lower part, of an upper part fitted onto the latter, and of the preparation as filling. During production, the lower part is first of all filled with the desired content. It is then closed by attachment of the upper part. During the filling and closing operations, the capsule lower parts and the closed capsules, respectively, are held in a capsule holder, wherein such a capsule holder has at least two capsule receptacles for capsules, generally also many more than two receptacles. Such a capsule holder is driven cyclically to various stations at which, among other things, the capsules are filled and closed and the finished capsules are ejected.
To achieve a high degree of process reliability, use is also increasingly being made of test stations at which tests are carried out to check the correct filling and correct closure of the capsules and/or other quality features. In the context of a 100% check, acceptable capsules can be distinguished from unacceptable capsules and appropriate measures can be taken.
If at least one capsule within a capsule holder is identified as being unacceptable, a removal process is initiated. For this purpose, the capsule holder passes through two different ejection stations. The capsules found to be unacceptable are ejected in one ejection station, and the capsules found to be acceptable are ejected in the other ejection station and forwarded for further processing. Ejectors are located at the individual stations and eject the respective capsules from their capsule receptacles. Simple structures are often used in which all of the ejectors of one station are driven and moved jointly. Therefore, if at least one single capsule from the total number of capsules in the capsule holder is identified as being unacceptable, all of the capsules located at the same time in the capsule holder in this cycle are jointly ejected. However, if no capsule was identified as unacceptable, then all of the capsules at the associated ejection station are ejected simultaneously and forwarded for further processing. The structure of devices of this kind is indeed simple, but there can be an undesirably high rate of rejection.
In a departure from this, there is now an increasing requirement for the removal of individual capsules. Therefore, if one or more capsules within a set of capsules are identified as being unacceptable, it is only these unacceptable capsules that should be ejected individually and discarded, while the remaining acceptable capsules from the same set of capsules are intended to be separately ejected and made available for further processing.
This assumes that the individual ejectors assigned to a capsule holder can be actuated independently of each other, wherein the device includes a drive unit for actuating the ejectors independently of each other in an ejection direction and in an opposite return direction. However, the capsule receptacles within a capsule holder are often arranged very close to each other, such that little installation space is available for an individual drive of the individual ejectors. This is made even more difficult if the capsule receptacles are arranged in two or more rows in the capsule holder. In addition to there being little installation space available, a high level of operational reliability is needed in view of the high cycle rates, since malfunctions of individual ejectors not only impair the ejection of individual capsules, they can also lead to malfunctions of the entire filling machine, including blockages and machine damage.